I have a similar problem. When loading the installation wizard it automatically finds my wine intallation, wich I select. Then I get the prompt "Select Tribunal installation media". As I understand I should select the Tribunal.esm file. I see this file in the file browser but it is greyed out like all other files and I cannot select it. It's the same when I opt out of installing the dlcs. It does not accept if I try to open the file by using the full path. There are no error messages I could give you.